The tale of the oily black crabs

I was standing on the beach in Kona, Hawaii, enjoying the beautiful tropical paradise. I was with the woman I love, and was doing what I enjoy, taking photographs. I had just focused on something when I heard a muffled scream. "Don't move", said Sweetie. "I think they see you." I slowly turned my head and saw nothing but paradise. Curiously, I looked at Sweetie to see what she had seen. She pointed to the breakwater scant inches from my backside - sorry, back AND side. I turned and came eyeball to eyeballs to eyeballs to eyeballs to eyeballs with the oily black crabs. They had silently snuck up behind me and I am convinced,were waiting to jump me.
Concerned only for my Sweetie's life, we departed the scene quickly.
As we were leaving, I noticed another man and his lady friend walking towards the breakwater. She mentioned his name (Howard) as she passed us. He was wearing a pale yellow Hawaiian shirt with a distinct pattern on it. And he had a camera.
We made our way to the sidewalk across the street, I saw him pose her on the rocks and back up to the breakwater. We turned the corner and went into a shop. When we came out (cue creepy music), we heard her calling his name. Again and again. I looked over towards the breakwater and saw, floating in the water, a tattered pale yellow Hawaiian shirt with a distinct pattern on it. As we walked to the safety of our hotel, all we could hear was the anguished calling of the name "Howard".

Actually the ugly little beasts ran away if you approached them, but this made it sound better.